Fibrous substrate with a solid hypohalite precipitate formed therein and process of making

ABSTRACT

A cleaning substrate which comprises at least one layer of a solid hypohalite precipitate, wherein the hypohalite precipitate is formed in situ on the layer of substrate material. A process for making a fibrous cleaning substrate comprising the steps of: a) providing at least one layer of fibrous material; b) exposing the fibrous layer to an aqueous alkaline earth salt solution; c) treating the fibrous layer with a hypochlorite solution; d) allowing the aqueous alkaline earth salt solution combine with the hypochlorite solution to form a solid hypochlorite precipitate around the fibers in the fibrous material and a liquid phase, and e) removing at least 65% of the liquid phase from the fibrous substrate.

CROSS-REFERENCE TO RELATED APPLICATIONS

This patent application is a continuation of copending U.S. patentapplication Ser. No. 12/960,297, filed Dec. 3, 2010.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates generally to a process for forming a solidhypochlorite precipitate on a fibrous substrate and the formedhypochlorite-releasing substrate. The process for forming a solidhypochlorite comprises the steps of: exposing one or more fibrousmaterials to an effective amount of aqueous alkaline earth saltsolution, treating the fibrous material with an effective amount ofhypohalite solution and allowing the alkaline earth salt solution toreact with the hypohalite solution to form solid hypochloriteprecipitate around the fibers in the fibrous material. Thehypochlorite-releasing substrate may have a variety of uses, includingbut not limited to, cleaning wipes, dishwashing towels for hand use orin dishwashers, toilet bowl cleaning pads, bath and shower cleaningpads, laundry sheets for the washer or dryer, water filters, wounddressing materials, carpet stain removal pads, air deodorizer pads, foodfreshness substrates, air filtration substrates, and water disinfectingsubstrates. The composition and process for making thehypochlorite-releasing substrate enables the liquid phase to be removedfrom the substrate creating a stable hypochlorite-releasing substratewhich is capable of rapid release of hypochlorite upon exposure tomoisture or liquid.

2. Background of the Invention

There is a need for a stable cleaning and disinfecting substrate, suchas a wipe or cleaning article that is capable of cleaning and removingresidues from soiled surfaces while simultaneously destroyingundesirable microorganisms, e.g. bacteria, mold, viruses, prions and thelike that colonize on common surfaces with which people come intocontact, such as door knobs, countertops, toilet seats, floors, beds,walls, and the like.

Hypohalite releasing compounds, such as the hypohalite and relatedcompounds that release active forms of hypohalite and/or halogens, areextremely effective disinfectants capable of destroying a wide range ofmicroorganisms. Hypohalite releasing antimicrobial compounds, and inparticular the hypohalite, constitute a class of strong chemicaloxidants possessing both cleaning and bleaching properties in additionto their antimicrobial properties making them superior to otherdisinfectants, such as quaternary ammonium biocides. The hypohaliteclass of chemical oxidants act to rapidly oxidize susceptible substancesfound in inorganic, organic and biological materials, rendering themmore easily removed from surfaces, and in the case of colored orpigmented materials, bleaching them to white or colorless end productsresulting in effective cleaning and stain removal from soiled surfaces.Owing to their strong oxidizing capability, hypohalite also possesinherent disinfection properties and additionally possess desirablecharacteristics including excellent aqueous solubility, mobility and ahighly dissociative ionic nature. A further advantage of the hypohaliteclass with regard to disinfecting, is the speed and efficacy with whichthey attack microorganisms and either destroy them or render themnon-viable following very short contact times. Yet a further advantageof the hypohalite is the wide susceptibility of many different types ofmicrobial pests to their strong oxidizing potential and essentially theabsence of any known microbe to develop an effective resistance againstthe action of these materials.

Typically, microbiologically contaminated surfaces seldom comprise onlythe microorganisms themselves, but include the presence of soils andother residues, including organic, inorganic and biological residuesassociated with the source of the microbiological contamination. Theseresidues, including, for example, saliva, bodily is fluids, blood andcommon soils such as foods, oils and dirt, not only host microorganisms,but can act to shield and protect the microorganisms from thedisinfectant action of non-hypohalite disinfectant materials.

One seeming disadvantage of the hypohalite class of materials is theirsusceptibility to decomposition, including self-decomposition andreactive decomposition owing to the interaction of the hypohalite withthe substrates and materials, which they contact during packaging andstorage. Particularly in the case of pre-wetted wipes, the disinfectinghypohalite composition is impregnated onto and interacts with theabsorbent carrier substrate during storage. Hence, freshly preparedsolutions or disinfectant articles utilizing these materials aretypically required to ensure adequate activity for ensuring effectivedisinfection of surfaces. Attempts have been made in the past to providea convenient disinfectant article by loading a liquid hypohalitesolution onto an absorbent substrate such as a wipe. One of the problemswith pre-loaded bleach wipes is that they lack sufficient stability toensure suitable disinfecting efficacy at time of use, particularlyfollowing typical storage times and/or less than ideal storageconditions representative of real world environments encountered in thehome, office, business, hospital or field where needed.

Another prior art embodiment of hypohalite loaded substrate which hasbeen used previously is a dry substrate which is loaded with a solidhypohalite which is adhered to the substrate using a binder or adhesiveagent. The problems with these dry loaded solid hypohalite substrates isthat the solid hypohalite may only be loaded on the exterior of thesurface of the substrate rather than evenly distributed throughout thesubstrate, the adhesive agent or binder may interferes with the quickrelease of the hypohalite, and if the particles size of the solidhypohalite is too large then the release rate may be too slow, but ifthe particles are too small the particles will fall off the substratetoo easily and will not be delivered to the desired point of use.

3. Description of the Related Art

The prior art covers numerous types of cleaning substrates andcompositions with hypochlorite. Wet cleaning wipes loaded withhypochlorite are know in the art and cleaning tools with pad loaded witha particulate hypochlorite which is adhered to the surface of the padwith a binder or adhesive are also well-known in the art. In addition,there are also solid tablets which include a solid hypochlorite whichare commonly used in toilet bowl cleaning tablets. Furthermore, thereare numerous processes for the formation of hypochlorite which are alsodescribed in the prior art. None of the prior art references describe aprocess for making a solid hypochlorite precipitate on a nonwovensubstrate or a fibrous substrate where the solid hypochlorite is formedon the substrate as a precipitate.

U.S. Pat. No. 7,008,600 to Kastigras et al. discloses a cleaningcomposition containing hypohalite and surfactant on a nonwoven substrateforming a wet cleaning wipe or pad. In the case of the Kastigrasinvention, the cleaning composition with the hypohalite and surfactantis formed and then it is loaded onto the nonwoven substrate. Inaddition, the disinfecting article of Kastigras is in a wet form on thesubstrate and must be stored in a sealable housing to ensure thestability of the substrate with the hypohalite solution. Unlike thepresent invention, the disinfecting article taught by Kastigras containsa hypohalite cleaning composition that is formed prior to being added tothe nonwoven substrate and the disinfecting article is loaded with anaqueous solution of hypohalite and surfactant. The use of a wet wipeloaded with an aqueous solution of hypochlorite is less desirable thanhaving a wipe with the liquid phase removed because there are stabilityand degradation problems that necessitate the use of a sealable housing.

U.S. Pat. No. 6,916,480 to Anderson et al. describes a wipe withcontrolled-release of antimicrobial agents which may include calciumhypochlorite particles. Similarly, U.S. Pat. No. 6,734,157 to Radwanski,et al. teaches a controlled-release wipe which may contain calciumhypochlorite particles adhered to the surface of the wipe. Theantimicrobial wipe taught by Anderson utilizes a polymer mixture tocontrol the release rate of the antimicrobial agent loaded on the wipe.In the case of Anderson and Radwanski, the antimicrobial wipes areformed by adhering solid particles of calcium hypochlorite to thesurface of the wipe with an adhesive or binding agent. Anderson does notteach a process for forming a solid hypochlorite precipitate on afibrous material in the absence of a binder or adhesive. One of thedeficiencies of this type of substrate where a solid bleach particle isadhered to the substrate is that the adhesive and/or the larger particlesize prevent rapid release of the hypochlorite when it is exposed tomoisture or liquid. If less adhesive is used or small particle sizehypochlorite is used then there is a problem with dusting because theparticles will not all stay on the substrate prior to use. In addition,the antimicrobial wipe taught by Anderson has solid hypochloriteparticles on the surface of the wipe rather than solid hypochloriteprecipitate formed around the fibers of the fibrous substrate, as in thepresent invention. In addition, the invention of Anderson requires thatthe hypohalite particles are on the surface of the wipe, whereas thepresent invention allows the hypohalite precipitate to be substantiallyevenly distributed throughout one or more layers of the substratematerial.

The use of a particulate form of solid hypochlorite adhered to thesurface of the substrate is less desirable than the present inventionbecause a binder or adhesive is necessary which adds additional expense.In addition, to make the solid calcium hypochlorite particles adhere tothe surface of the wipe they cannot be so fine that they fall off thesurface of the substrate leading to dusting or exfoliation.Unfortunately, particles that are large enough to effectively adhere tothe surface of the substrate means there is less surface area exposed tomoisture or fluid which means a slower release rate of hypochlorite thanthat of the present invention.

U.S. Pat. No. 4,513,459 to Doughty describes a bleach cake in a filtersleeve which is used in toilet bowl tanks to clean and disinfect. Thebleach cake in Doughty comprises a solid calcium hypochlorite and thefilter sleeve surrounds the bleach cake to prevent particles from thecake breaking off and obstructing flow of the water into the toilet bowlfrom the tank. The invention of Doughty differs from the presentinvention because the bleach cake is formed as a separate solid materialthat is then encased in the filter sleeve whereas the present inventioninvolves the formation of a solid hypochlorite precipitate around thefibers of a fibrous substrate.

The prior art references teach wet loaded hypochlorite containing wipeswhich have stability and degradation problems unless they are stored insealable containers which do not allow light or air exposure. The priorart also teaches wipes loaded with solid particulate calciumhypochlorite particles using an adhesive or binder which have the addedexpense of an adhesive and do not release hypochlorite as efficiently asthe present invention. In addition the prior art also teaches bleachcakes, but these bleach cakes are not formed on a fibrous substrate andare primarily a solid bleach rather than a combination of solid bleachand fibrous material. In addition, there are references about theformation of calcium hypochlorite but none which talk about hypochloriteformation on a fibrous substrate. In view of the prior art, there is aneed for a process for forming a solid hypochlorite precipitate on afibrous substrate and a hypochlorite releasing substrate that overcomesthe disadvantages and shortcomings associated with prior art processesand hypochlorite releasing substrates.

SUMMARY OF THE INVENTION

The present invention relates to a hypohalite-releasing substratecomprising: a) at least one fibrous layer comprising fibers selectedfrom the group consisting of: natural cellulose, regenerated cellulose,polyester, acrylic, nytril, cellulose ester, olefin, vinyl and anycombinations or mixtures thereof, b) a solid hypohalite precipitateformed around the fibers and in the interstices of the fibrous layerselected from mixtures and combinations of hypohalite salts.

In one embodiment of the invention, the hypohalite-releasing substrateis a hypochlorite-releasing substrate and the hypohalite precipitate isa hypochlorite precipitate selected from the group consisting of:hypochlorite monohydrate salt, hypochlorite dihydrate salt, hemibasichypochlorite salt, monobasic hypochlorite salt, dibasic hypochloritesalt, anhydrous hypochlorite salt, and mixtures and combinationsthereof. In another embodiment of the invention, the substrate issubstantially free of any glues, binders, adhesives, tackifying agentsor the like. In another embodiment wherein the solid hypochloriteprecipitate is uniformly distributed throughout the first fibrous layer.In another embodiment of the invention, the hypochlorite-releasingsubstrate is substantially dry-to-the-touch and thehypochlorite-releasing substrate comprises less than 35% of a liquidphase, preferably less than 25% of a liquid phase, more preferably lessthan 20% of a liquid phase or even less than 10% of a liquid phase.

The present invention also includes a process for forming a solidhypochlorite precipitate on a fibrous substrate and makinghypochlorite-releasing substrate. The process of forming a solidhypochlorite precipitate on a fibrous substrate comprises the steps of:(a) providing at least one layer of fibrous material, (b) exposing thefibrous material to an effective amount of aqueous alkaline earth saltsolution, (c) treating the fibrous layer with an effective amount ofhypochlorite solution and, (d) allowing the aqueous alkaline earth saltsolution to combine with the hypochlorite solution to form a solidhypochlorite precipitate around the fibers in the fibrous material. Inone embodiment of the invention, the process for forming the solidhypochlorite precipitate on a fibrous substrate includes removing atleast 65% the liquid phase from the substrate, preferably removing atleast 75% or at least 80% or 90% of the liquid phase from the substrate.The liquid phase may be removed from the substrate by a heating, drying,evaporating, vacuum drying or stripping, or any other suitable methodfor removing liquid from the substrate.

In another embodiment of the invention, there are at least two fibrousmaterials wherein the first fibrous material is exposed to an alkalineearth salt solution and the second fibrous material is treated with ahypochlorite solution and then the first and second fibrous materialsbrought into contact with one another to cause the formation of a solidhypochlorite precipitate on the fibrous substrate. In this embodimentthe substrate may contain two or more layers of fibrous materials. Theremay be additional layers of substrate material coating an alkalinesolution, or a hypohalite solution, or additives such as surfactants,dyes, builders, pH adjustors, fragrances, abrasives, etc. There may alsobe additional layers of substrate materials which are fibrous ornon-fibrous which may be un-loaded or loaded with additional cleaningcompositions or additives.

In one embodiment, the hypochlorite-releasing fibrous substrate may be acleaning wipe or pad. In another embodiment of the invention, thehypochlorite-releasing substrate may be a filtration device for cleaningand disinfecting water or air. In another aspect of the invention, thehypochlorite-releasing substrate may used for as a wound dressing. Inanother aspect of the invention, the hypochlorite-releasing substratecan be used as a source for generating bleach vapor. In one embodiment,the hypochlorite-releasing substrate may be used in conjunction withhousehold appliances, including but not limited to, dishwashers, laundrymachines, dryers, and/or vacuums to clean and disinfect various surfacesaround the home.

The hypochlorite-releasing substrate may be created to provide asufficient amount of active hypochlorite which remains effective for anextended period of time to reliably disinfect hard surfaces such ascountertops, toilet seats, door knobs and the like commonly found in thehome, hospital, food service and other industries. In another embodimentof the invention, the hypochlorite-releasing substrate may be loadedwith relatively low levels of hypochlorite to provide a more mildsolution which may be used for air or water sanitization or to cleansoft surfaces without causing discoloration. The amount of solidhypochlorite precipitate on the fibrous substrate will depend on thedesired application and use of the substrate.

Further features and advantages of the present invention will becomeapparent to those of ordinary skill in the art in view of the detaileddescription of preferred embodiments below, when considered togetherwith the attached claims.

DETAILED DESCRIPTION OF THE INVENTION

Before describing the present invention in detail, it is to beunderstood that this invention is not limited to particularlyexemplified systems or process parameters that may, of course, vary. Itis also to be understood that the terminology used herein is for thepurpose of describing particular embodiments of the invention only, andis not intended to limit the scope of the invention in any manner.

All publications, patents and patent applications cited herein, whethersupra or infra, are hereby incorporated by reference in their entiretyto the same extent as if each individual publication, patent or patentapplication was specifically and individually indicated to beincorporated by reference.

It must be noted that, as used in this specification and the appendedclaims, the singular forms “a,” “an” and “the” include plural referentsunless the content clearly dictates otherwise. Thus, for example,reference to a “salt” includes two or more such salts.

Unless defined otherwise, all technical and scientific terms used hereinhave the same meaning as commonly understood by one of ordinary skill inthe art to which the invention pertains. Although a number of methodsand materials similar or equivalent to those described herein can beused in the practice of the present invention, the preferred materialsand methods are described herein.

The “hypohalite-releasing substrate” or “hypochlorite-releasingsubstrate” can be used as a disinfectant, sanitizer, and/or sterilizer.As used herein, the term “disinfect” shall mean the elimination of manyor all pathogenic microorganisms on surfaces with the exception ofbacterial endospores. As used herein, the term “sanitize” shall mean thereduction of contaminants in the inanimate environment to levelsconsidered safe according to public health ordinance, or that reducesthe bacterial population by significant numbers where public healthrequirements have not been established. An at least 99% reduction inbacterial population within a 24 hour time period is deemed“significant.” As used herein, the term “sterilize” shall mean thecomplete elimination or destruction of all forms of microbial life andwhich is authorized under the applicable regulatory laws to make legalclaims as a “Sterilant” or to have sterilizing properties or qualities.

In the application, effective amounts are generally those amounts listedas the ranges or levels of ingredients in the descriptions, which followhereto. Unless otherwise stated, amounts listed in percentage (“%'s”)are in weight percent (based on 100% active) of the cleaning compositionalone, not accounting for the substrate weight. Each of the notedcleaner composition components and substrates is discussed in detailbelow.

As used herein, the terms “fibrous substrate”, “fibrous layer” and“fibrous materials” are intended to include any material that that isformed of fibers. Examples of fibrous substrates include, but are notlimited to nonwovens, sponges, wipes, pads, filtration devices, laundrysheets, bandages, fiber strands, cleaning heads and similar materialswhich can be attached to a cleaning implement, such as a floor mop,handle, or a hand held cleaning tool, such as a toilet cleaning device.

As used herein, “disposable” is used in its ordinary sense to mean anarticle that is disposed or discarded after a limited number of usageevents, preferably less than 25, more preferably less than about 10, andmost preferably less than about 2 entire usage events.

As used herein, “fibers” included hypochlorite stable fibrous materials,including but not limited to, natural cellulose, regenerated cellulose,polyester, acrylic, nytril, cellulose ester, olefin, vinyl and anycombinations or mixtures thereof. In one embodiment of the invention,the fibrous material comprised fibers selected from the group consistingof: polypropylene, polyethylene, polyester and mixtures and combinationsthereof including bicomponent and multicomponent fibers.

As used herein, “wiping” refers to any shearing action that thesubstrate undergoes while in contact with a target surface. Thisincludes hand or body motion, substrate-implement motion over a surface,or any perturbation of the substrate via energy sources such asultrasound, mechanical vibration, electromagnetism, and so forth.

As used herein, the terms “nonwoven” or “nonwoven web” means a webhaving a structure of individual fibers or threads which are interlaid,but not in an identifiable manner as in a knitted web. Nonwoven webshave been formed from many processes to form materials, such as, forexample, spunbond, meltblown, spunbond-meltblown-spunbond (SMS), carded,wetlaid, airlaid, thermalbonded, hydroentangled, through-air-bonded,needled, chemical bonded and any combinations thereof.

As used herein, the term “solid hypohalite precipitate” generallyincludes a precipitate that is formed by the reaction of an effectiveamount of an aqueous alkaline earth salt solution and a hypohalitesolution. The hypohalite precipitate may be hypohalite salt or a mixtureor combination of various hypohalite salts. Similarly, the term “solidhypochlorite precipitate” generally includes a precipitate that isformed by the reaction of an effective amount of an aqueous alkalineearth salt solution and a hypochlorite solution. More specifically, the“solid hypochlorite precipitate” may be crystalline or amorphous andcomprises one or more salts selected from the group consisting of:hypochlorite dehydrate salt, hemibasic hypochlorite salt, monobasichypochlorite salt, dibasic hypochlorite salt, and any mixtures andcombinations thereof.

The term “alkaline earth salt solution”, as used herein, means asolution selected from the group consisting of: magensium chloride,calcium chloride, calcium hydroxide, magnesium hydroxide and mixturesthereof.

The term “hypochlorite solution”, as used herein, is meant to mean asolution comprising compounds selected from the group consisting of:sodium hypochlorite, potassium hypochlorite, lithium hypochlorite,calcium hypochlorite, magnesium hypochlorite, hypochorlous acid andmixtures and combinations thereof.

The term “liquid phase”, as used herein, refers to water, solvents andany other liquids that may be absorbed into the substrate material. Inone embodiment of the invention, about 65% to 100% of the liquid phaseis removed from the fibrous layer containing the hypohalite precipitate.The layer with the hypohalite precipitate may be substantiallydry-to-the-touch after the removal of most of the liquid phase. Inanother embodiment of the invention, at least 65% of the liquid phase isremoved from the entire substrate which may be one or more layers ofmaterial. This means that at least 65% of the liquid on the substratewhich may be water, solvent, any other liquids or combinations thereofis removed from a single layer of fibrous material in the substrate, ormultiple layers of substrate materials or then entire substrate.

The term “additive”, as used herein, is meant to mean an optionalingredient to the composition, which included but is not limited to,emulsifiers, pH adjusters, silicones, surfactants, soil release agents,soil release polymers, antistatic agents, fragrances, fragranceextenders, antimicrobial additives, dyes, colorants, viscosity controlagents, foaming agents, peralizing agents, opacifying agents,anitxoidants, sunscreens, dye transfer inhibitors, dye fixative agents,dispersants, chlorine scavengers, wetting agents, electrolytes, enzymes,brightners, heavy metal chelating agents, fabric softeners, soilsuspending agents, thickeners and mixtures thereof. In a preferredembodiment of the present invention, it is preferred that any additivesare hypochlorite stable.

The term “surfactant”, as used herein, is meant to mean and include asubstance or compound that reduces surface tension when dissolved inwater or water solutions, or that reduces interfacial tension betweentwo liquids, or between a liquid and a solid. The term “surfactant” thusincludes anionic, nonionic and/or amphoteric agents.

The term “consisting essentially of” as used herein, limits the scope ofa claim to the specified materials or steps “and those that do notmaterially affect the basic and novel characteristic(s)” of the claimedinvention. In re Herz, 537 F.2d 549, 551-52, 190 USPQ 461, 463 (CCPA1976) (emphasis in original). See MPEP 2111.03 For the purposes ofsearching for and applying prior art under 35 U.S.C. 102 and 103, absenta clear indication in the specification or claims of what the basic andnovel characteristics actually are, “consisting essentially of” will beconstrued as equivalent to “comprising.” See, e.g., PPG, 156 F.3d at1355, 48 USPQ2d at 1355. See MPEP 2111.03

Processes for Making a Substrate with a Hypohalite Precipitate

The present invention relates to a process for creating a stablehypochlorite-releasing substrate which is substantially dry-to-the-touchand is substantially free of binders, adhesives, tackifying agents andthe like. The method of the present invention involves forming a solidhypochlorite precipitate on a fibrous substrate material. The reactionused to form the solid hypochlorite precipitate is as follows:CaCl₂+2NaOCl - - -

Ca(OCl)₂+2NaCl

The process of forming a solid hypochlorite precipitate on a fibroussubstrate comprises the steps of: (a) providing at least one layer offibrous material, (b) exposing the fibrous material to an effectiveamount of aqueous alkaline earth salt solution, (c) treating the fibrouslayer with an effective amount of hypochlorite solution and, (d)allowing the aqueous alkaline earth salt solution to combine with thehypochlorite solution to form a solid hypochlorite precipitate aroundthe fibers in the fibrous material. In one embodiment of the invention,the process for forming the solid hypochlorite precipitate on a fibroussubstrate includes removing at least 65% the liquid phase from thesubstrate. In another embodiment of the invention, at least 75% of theliquid phase is removed from the substrate, preferably removing at least80% of the liquid phase from the substrate, more preferably removing atleast 85% of the liquid phase from the substrate, and most preferablyremoving at least 90% of the liquid phase from the substrate. The liquidphase may be removed from the substrate by a heating, drying,evaporating, vacuum drying and/or stripping and any other suitablemethod or combination of methods for removing liquid from the substrate.

In one embodiment of the invention, the alkaline earth salt solutionselected from the group consisting of: magnesium chloride, calciumchloride, calcium hydroxide, magnesium hydroxide and any mixtures orcombinations thereof. In another embodiment, the hypochlorite solutioncomprises compounds selected from the group consisting of: sodiumhypochlorite, potassium hypochlorite, lithium hypochlorite, calciumhypochlorite, magnesium hypochlorite, hypochlorous acid, and anymixtures of combinations thereof. In an alternative embodiment, thesolid hypochlorite precipitate contains salts selected from the groupconsisting of: hypochlorite monohydrate salt, hypochlorite dihydratesalt, hemibasic hypochlorite salt, monobasic hypochlorite salt, dibasichypochlorite salt, anhydrous hypochlorite salt, and mixtures andcombinations thereof. The solid hypochlorite precipitate may beamorphorous or crystalline.

In one embodiment of the invention, a nonwoven substrate material isdipped and fully saturated with a calcium chloride solution.Concentrations of between about 10% to about 55% by weight are desirablefor forming the calcium chloride solution. The active level of thecalcium chloride solution may be used to control the loading level ofthe resulting solid hypochlorite precipitate desired on the substrate.The nonwoven substrate material is then dipped into or sprayed with astochiometric amount of a sodium hypochlorite solution. The strength ofthe solution is dependent upon the desired level of water removal andthe water absorption characteristics of the nonwoven substrate material.Optionally, the substrate may be sprayed with sodium carbonate andlauric acid. In this embodiment of the invention, the nonwoven substratemay absorb between 10% and 1000% by weight of its own mass. Theresulting loading ratio of substrate weight to liquid weight is about0.1:1 to about 1:100, preferably about 0.1:1 to about 1:10, mostpreferably about 1:2 to about 1:8.

The formation of the solid hypochlorite precipitate from the two liquidreagents in the nonwoven substrate is fully incorporated into thenonwoven structure after at least 50% or more of the liquid phase isremoved from the substrate by heating, drying, evaporation, etc. Theconcentration of the sodium hypochlorite solution will determine theamount of heating or drying time required to remove the excess liquidphase from the substrate. Sodium hypochlorite concentrations of about 1%to about 10% by weight are desirable. The ionic strength of the solutionwill drive the reaction rate. Equimolar salt solutions and higher ionicstrength solutions are feasible using this process.

Additional layers of substrate materials may be included along withlayer of substrate containing the hypochlorite precipitate. For example,another layer of nonwoven material comprising foaming surfactants orsurfactant combinations such as: secondary alkyl sulfate (SAS)surfactants and amine oxide surfactants, caustic neutralized coco fattyacid, and caustic neutralized lauric acid. These foaming surfactantcombinations are intended to be exemplary combinations, but they do notlimit the possibilities of other suitable surfactants or combinationsthat may be more desirable for alternative cleaning compositions andcleaning substrates. The substrate layer comprising foaming surfactantsmay be embedded into the structure of the nonwoven substrate usingliquid solutions that change phase with temperature or co-precipitate asa solid surfactant precipitate at the same time as the hypochloriteprecipitate is being formed. The surfactant precipitate may be formed insitu on one of the layers of substrate material. The surfactantprecipitate may be evenly distributed throughout the width and/or lengthof one or more fibrous layers of the substrate material. Alternatively,the solid surfactant precipitate may distribute only on the top of oneor more of the fibrous layers. A substrate layer comprising foamingsurfactants may be formed separately from the hypochlorite precipitatelayer and then joined together once the hypochlorite precipitate layeris substantially dry.

The fibrous material may be exposed to the aqueous alkaline earth saltsolution by a variety of different means, including but not limited todipping, spraying, dosing, dripping, soaking, showering, misting,printing or any other suitable means for applying the aqueous alkalineearth salt solution to the fibrous substrate material. In one embodimentof the invention, the entire layer of fibrous material or entiremultiple layers of fibrous materials are treated with the aqueous earthsalt solution. In another embodiment of the invention, only portions ofthe layer of fibrous material are treated with the alkaline earth saltsolution so that the treatment is not uniformly applied across an entirelayer of the substrate material.

Similarly, the fibrous material may be treated with an effective amountof hypochlorite solution by a variety of different means, including butnot limited to dipping, spraying, dosing, dripping, soaking, showering,misting, printing or any other suitable means for applying thehypochlorite solution to the fibrous substrate material. In oneembodiment of the invention, the entire layer of fibrous material orentire multiple layers of fibrous materials are treated with thehypochlorite solution. In another embodiment of the invention, onlyportions of the layer of fibrous material are treated with thehypochlorite solution so that the treatment is not uniformly appliedacross an entire layer of the substrate material.

In another embodiment of the invention, at least one fibrous materialmay be treated with an effective amount of hypochlorite solution by avariety of different means, including but not limited to dipping,spraying, dosing, dripping, soaking, showering, misting, or any othersuitable means for applying the aqueous alkaline earth salt solution tothe fibrous substrate material. Then the fibrous material treated withan effective amount of hypochlorite solution is exposed to chlorine gasand some of the liquid phase is removed to create a soild hypochloriteprecipitate on the fibrous substrate.

In another embodiment of the invention, there are at least two fibrousmaterials wherein the first fibrous material is exposed to an alkalineearth salt solution and the second fibrous material is treated with ahypochlorite solution and then the first and second fibrous materialsbrought into contact with one another to cause the formation of a solidhypochlorite precipitate on the fibrous substrate. In this embodimentthe substrate may contain two or more layers of fibrous materials. Theremay be additional layers of substrate material coating an alkalinesolution, or a hypohalite solution, or additives such as surfactants,dyes, builders, pH adjustors, fragrances, abrasives, etc. There may alsobe additional layers of substrate materials which are fibrous ornon-fibrous which may be un-loaded or loaded with additional cleaningcompositions or additives.

Substrate Materials

Suitable substrates may be provided by a variety of sources, includingwoven and non-woven webs, fabrics, foams, sponges, films and similarmaterial constructs capable of being treated with an aqueous alkalineearth salt solution and with an effective amount of a hypochloritesolution. In one embodiment, films may be a suitable substrate. Suitablefilms may be perfereated and/or porous films or slit films whichcomprise flat fibers. In one embodiment, the substrate has a least onelayer of fibrous material wherein the fibers are selected from the groupconsisting of: polypropylene, polyethylene, polyester and any mixturesor combinations thereof including bicomponent and multicomponent fibers.Additional layers of the substrate may comprise a wide variety ofmaterials, including but not limited to, natural fibers, syntheticfibers, foams, abrasive materials, sponges, moisture impermeablematerials or layers, and any combinations or permutations thereof. Thesubtrate may be a layered material with any combination of materials,including but not limited to, woven and non-woven webs, fabrics, foams,sponges, films and similar material constructs which are capable ofcarrying a solid hypochlorite precipitate.

In an alternate embodiment of the invention the treatment of the fiberswith the hypochlorite solution and/or the alkaline earth salt solutionmay occur at the same time the fibers are being formed into a fibrousweb. For example, as the fibers are being formed into a fibrous web theycould pass through wet sections or treatment areas or processes wherethey are treated with an alkaline earth salt solution and then a secondwet treatment where the fibers are treated with hypochlorite solutionbefore or concurrently with the process of forming the fibers into awoven or non-woven substrate. Alternatively, fibers may be treated withan alkaline earth salt material and formed into a woven or non-wovensubstrate and then treated with a hypochlorite solution or chlorine gas.Similarly, fibers may be treated with a hypochlorite solution and formedinto a woven or non-woven substrate and then treated with an alkalineearth salt solution. In another embodiment, a portion of the fibers maybe treated with a hypochlorite solution and a portion of the fibers maybe treated with an alkaline earth salt solution. When the treatedhypochlorite fibers and the treated alkaline earth salt fibers areformed into the fibrous web the solid hypochlorite precipitate forms. Invarious embodiments of the invention, the solid hypochlorite precipitatetherefore may be formed on individual fibers, on a fibrous websubstrate, or on portions of a fibrous web substrate where the treatedhypochlorite fibers and the treated alkaline earth salt fibers come intocontact with one another.

In another embodiment of the invention, the substrate material is a filmor resin that is extruded with the alkaline earth salt salt(s) alreadyin the film or resin. The extruded fibers containing the alkaline earthsalts can be treated with a hypochlorite solution or a chlorine gas. Ifa choline gas is used with the extruded fibers containing the alkalineearth salt(s) then the entire process is a dry process and therefore theadditional step of removing the liquid phase is not necessary to formthe solid hypochlite precipitate.

The substrate may comprise a single layer or multiple layers of one ormore materials. The substrate may also comprise a combination of one ormore materials and/or one or more forms of materials. The multiplelayers or multiple forms of materials are bonded to each other bysuitable means to prevent separation. For example, a sheet of onematerial may be combined with a second sheet of a second material andbonded together by suitable means. Suitable means of bonding sheetstogether includes, by way of example and not by way of limitation,hydroentangling, embossing, adhesion and heat or sonic welding. Afurther example, a non-woven sheet of one material may be combined witha second material formed into deformable and compressible foam, andbound together by a suitable means. In this manner, all conceivablecombinations of materials may be combined to provide useful articles fora variety of cleaning and disinfecting requirements.

In one embodiment of the invention, the substrate comprises at least onelayer of fibrous material which is a non-woven material selected fromthe group consisting of: spunbond, meltblown, SMS, carded, wetlaid,airlaid, thermalbonded, hydroentangled, through-air bonded, needled,chemical bonded, coform and combinations thereof. The substrate materialwhich is loaded with the solid hypohalite precipitate may be formed on alayer of fibrous material which is already part of a single ormultilayer substrate which is ready for use. Alternatively, the solidhypohalite precipitate may be formed on a layer of fibrous material thatmaybe later joined into a multilayer substrate or tool or may beadditionally processed by adding texture, additives or other componentsto form a finished hypohalite-releasing article or tool.

In one embodiment, the substrates have a series of apertures, whichimprove substrate stability, because apertures can decrease the overallsurface area by up to 20%. For cleaning wipes, the substrate ispreferred to be in sheet form. Preferably, the cross-sectional thicknessdimension of the substrate sheet is proportionally smaller than eitherits approximate width or length dimension in order to provide at leastone surface whose surface area is sized appropriately with respect tothe intended surface to be treated with the disinfectant article. Thecleaning wipe substrate may be formed into individual sheets or wipes oras a continuous sheet. In continuous sheet form, it is preferred toprovide means, such as partial tears or perforations across at least onedimension of the sheet, such that the continuous sheet may be subdividedprior to use to a suitable size for the particular need at hand.

The substrate may comprise a wipe, cleaning pad or cleaning head for atool. The wipe or cleaning pad can be used with the hand, or as part ofa cleaning implement attached to a tool or motorized tool, such as onehaving a handle. A hypohalite-releasing substrate used as a cleaninghead with a tool may be particularly useful for cleaning bathtubs,toilets, showers, sinks, and other suitable household surfaces. Examplesof tools using a wipe or pad include U.S. Pat. No. 6,611,986 to Seals,WO00/71012 to Belt et al., U.S. Pat. App. 2002/0129835 to Pieroni andFoley, and WO00/27271 to Policicchio et al.

Further, the substrate can be combined with non-absorbent materials,preferably in the form of films, sheets or blocks. Preferably, thenon-absorbent materials are liquid impervious, in that they do notpermit the passage of the hypohalite compositions which are releasedfrom the substrate in the presence of moisture or liquid. In oneexample, the non-absorbent materials may be bonded to one side of asuitable hypohalite-releasing substrate creating a layered substrate.The layered substrate has a liquid impervious barrier to prevent passageof the disinfectant composition from the absorbent material to theoutside surface of the barrier material. Thus the liquid imperviousbarrier allows the user to handle the layered disinfectant articlewithout direct contact with the disinfectant loaded side of the layeredarticle. Another example is a thin liquid impervious plastic sheetbounded to a hypochlorite-releasing substrate layer, whereby the usercontacts the plastic sheet during use rather than contacting thehypochlorite-releasing layer or layers of the substrate while wiping thesurface to be treated.

According to the present invention, the substrate layers and materialsmay be produced by any method known in the art. For example, non-wovenmaterial substrates can be manufactured by dry forming techniques suchas air laying or wet laying such as on a paper making machine. Othernon-woven manufacturing techniques, such as hydroentangling, melt blown,spun bonded, needle punched and related methods may also be used.However, it is preferred that the substrate be made substantially freeof binder or latex and other impurities that may degrade or interactwith the solid hypochlorite precipitate. Hydroentrangling manufacturingtechniques using high speed water jets are generally preferred due tothe high density matrices produced and the high degree of cleanliness ofthe resulting non-woven articles produced by this method.

Suitable substrates or substrate layers are generally selected fromman-made and synthetic construction materials or substrates, preferablyincluding synthetic polymers. For good cleaning, absorption, handlingand loading characteristics, it is desirable that the absorbent carriermaterials be in the form of fiber, webs or foams of the suitableconstruction materials.

Suitable forms of employing fibers include woven and non-wovenstructures. Suitable woven structures include, by way of example and notby way of limitation, meshes, screens, knits, fabrics and othersimilarly woven structures, of sufficiently high fiber count andstrength to be handled by typical machinery and process equipment neededfor forming, cutting and packaging the disinfectant articles, preferablywhen in a dry state. Suitable woven structures include those structuresthat are of sufficiently high fiber count and strength to be dispensedand handled during use, preferably when in a dry state and/or when in awetted state.

Suitable woven and non-woven structures are composed of fibers with bothsufficient fiber sizes and fiber densities to provide some absorptioncapacity and enable loading of a sufficient quantity of the disinfectantsolution so as to provide for effective treatment of surfaces. Suitablefiber sizes and may vary depending on the choosen application for thesubstrate with the in situ hypochlorite precipitate. Denier is aweight-per-unit-length measurement of a linear material defined as thenumber of grams per 9000 meters. For example, in one emboidment standardto larger denier size are preferable because they can improve thestability of the substrates which makes them effective for a longerperiod of time. In this emboidment, the fibers in the substrate willhave about 1.5 to 6.0 denier. In this embodiment, suitable non-wovenstructures include those structures that are of sufficiently high fibercount and strength to be dispensed from the packaging articles, withoutsignificant deformation, tearing or ripping, and handled during use,without unraveling, abrading or tearing, preferably when in a wettedstate.

In another embodiment of the invention, smaller fiber sizes, less than 3denier, or less than 2 deniner, or less and 1 denier, or nanofibers, arepreferred. Smaller fiber sizes generally improve absorbency, meteringrelease and provide increased surface area creating more space forhypochlorite precipitate to form. For example, for a substrate used in awound care application may comprise nanofibers to provide lots ofsurface area and metered/controlled release of the hypochlorite andoptional other actives from the substrate. In an alternative example, atoilet wand cleaning head may employ larger fibers in a hi-loftsubstrate which are strong fibers which will withstand abrasive cleaningor scrubbing of a toilet bowl. In another exemplary embodiment, asubstrate with in situ hypochlorite precipitate that is used forfiltration devices may contain trilobal or flat fibers to aid filtrationprocesses and configurations. In essence, the size, shape, compositionand arrangement of the fibers in the substrate material may be changedin a variety of different ways to suit a particular application or use.

Suitable substrates employed for constructing the substrate layercomprising the hypohalite precipitate may be provided by a variety ofsources, and include all suitable substrates that are hypohalite stable,in that they undergo no significant degradation. That is, suitablesubstrates that undergo no significant chemical or physical change instructure, properties or form, owing to contact with the disinfectantcompositions employed in the present invention, even after extendingcontact or storage times under representative storage conditions.Preferred are suitable substrates that do not cause significantdegradation of the associated or absorbed disinfecting compositions,that is, substrates that do not catalyze or significantly accelerate thedecomposition of the associated hypohalite compositions.

Suitable materials of construction generally include synthetic polymersubstrates, such as, by way of example and not by way of limitation,polyethylene terephthalate (PET), polyethylene (PE), high densitypolyethylene (HDPE), low density polyethylene (LDPE), polyvinyl chloride(PVC), chlorinated polyvinylidene chloride (CPVC), polyacrylamide(ACAM), polystyrene (PS), polypropylene (PP), polycarbonate (PC),polyaryletherketone (PAEK), poly(cyclohexylene dimethylenecyclohexanedicarboxylate) (PCCE), poly(cyclohexylene dimethyleneterephthalate) (PCTA), poly(cyclohexylene dimethylene terephtalate)glycol (PCTG), polyetherimide (PEI), polyethersulfone (PES),poly(ethylene terephthalate) glycol (PETG), polyketone (PK),poly(oxymethylene); polyformaldehyde (POMF), poly(phenylene ether)(PPE), poly(phenylene sulfide) (PPS), poly(phenylene sulfone) (PPSU),syndiotactic polystyrene (syn-PS), polysulfone (PSU),polytetrafluoroethylene (PTFE), polyurethane (PUR), poly(vinylidenefluoride) (PVDF), polyamide thermoplastic elastomer (TPA), polybutylene(PB), polybutylene terephthalate (PBT), polypropylene terephthalate(PPT), polyethylene naphthalate (PEN), polyhydroxyalkanoate (PHA),poly(methyl)methacrylate (PMMA) and polytrimethylene terephthalate(PTT).

Suitable materials of construction also include copolymers made from thefollowing monomers: polyethylene terephthalate (PET), polyethylene (PE),polypropylene (PP), acrylonitrile-butadiene-styrene (ABS),acrylonitrile-styrene-acrylate (ASA), ethylene-propylene (E/P),ethylene-vinyl acetate (EVAC), methylmethacrylate-acrylonitrile-butadiene-styrene (MABS),methacrylate-butadiene-styrene (MBS), melamine-formaldehyde (MF),melamine-phenol-formaldehyde (MPF), phenol-formaldehyde (PF),styrene-butadiene (SB), styrene-maleic anhydride (SMAH), copolyesterthermoplastic elastomer (TPC), olefinic thermoplastic elastomer (TPO),styrenic thermoplastic elastomer (TPS), urethane thermoplastic elastomer(TPU), thermoplastic rubber vulcanisate (TPV), copolymer resins ofstyrene and acrylonitrile (SAN), styrene butadiene copolymer (SBC) andvinyl acetate-ethylene copolymer (VAE).

In one embodiment of the invention, the entire substrate issubstantially free, preferably devoid, of any binders, adhesives, gluestacifiying agents, latex materials or the like. In another embodiment ofthe invention, at least one fibrous layer of the substrate materialwhich contains the hypochlorite precipitate is substantially free of anybinder, adhesives, glues, tacifiying agents, latex materials, or thelike. In this embodiment of the invention, binders and adhesives may beused in the substrate as long as they are kept separate from thehypohalite precipitate. Binders, adhesives or the like may be in otherlayers of the substrate material for the purpose of join layers ofmaterials together, adhering abrasive materials or a variety of otherpurposes know in the art.

Substantial elimination of binders and latexes, and the like, can beaccomplished by pre-washing the dry absorbent carrier in soft, distilledor de-ionized water or other solvents, or by using a substantiallybinder-free and latex-free process, such as hydroentangling (also knownin the art as spunlace technology). More specifically, in thehydroentangling process, a fibrous web is subjected to high-velocitywater jets, preferably employing de-ionized, distilled or soft waterthat entangle the fibers. The non-woven material may then be subjectedto conventional drying and wind-up operations, as known to those skilledin the art. Since the hydroentangling process precludes the use ofbinders, and can be used to wash off at least a portion of the fiberlatexes, it is one of the most preferred processes for use in themanufacture of materials of construction of the present invention.Suitable materials of construction that are readily available incommerce include, but are not limited to, the SONTARA® brand ofnon-woven fabrics produced by Dupont. Representative materials include100% polyester substrate materials designated SONTARA® 8001, 8005H, 8010and 8061, and 50% polyester/50% Dacron® blends designated SONTARA® 8100and including hydrophilically modified 100% polyester substrate materialdesignated SONTARA® 8005H. Additional examples include materialscommercially available from Polymer Group Inc, including 100% spunlacedpolyester and polypropylene materials designated M001, M022, M040X,CG003, CG005, CG2009, M017, N2006 and T133. Representative materialsalso include spunlaced 100% polyester materials, designated as 350160and 10203-003, available from Jacob Holms Industries.

Hypohalite Solution Components

Suitable hypohalite compounds may be provided by a variety of sources,including bleaches that lead to the formation of positive halide ionsand/or hypohalite ions, as well as bleaches that are organic basedsources of halides, such as chloroisocyanurates, haloamines, haloimines,haloimides and haloamides, or mixtures thereof. These bleaches are allcapable of producing hypohalite-bleaching species in situ. Preferredhypohalite bleaches for use herein include the alkali metal and alkalineearth metal hypochlorites, hypobromites, hypoiodites, chlorinatedtrisodium phosphate dodecahydrates, potassium and sodiumdichloroisocyanurates, potassium and sodium trichlorocyanurates,N-chloroimides, N-chloroamides, N-chlorosulfamide, N-chloroamines,chlorohydantoins, such as dichlorodimethyl hydantoin and chlorobromodimethylhydantoin, or mixtures thereof.

In a preferred embodiment the hypohalite composition comprises an alkalimetal and/or alkaline earth metal hypochlorite, or mixtures thereof.More preferably, the hypohalite composition comprisies an alkali metaland/or alkaline earth metal hypochlorite selected from the groupconsisting of sodium hypochlorite, potassium hypochlorite, magnesiumhypochlorite, lithium hypochlorite and calcium hypochlorite, andmixtures thereof. Even more preferably, the hypohalite solutioncomprises sodium hypochlorite.

Hypohalite Precipitate

The hypohalite precipitate is formed when the fibrous substrate istreated with an alkaline earth salt solution and a hypohalite solutionand then at least 65% of the liquid phase is removed from the substratematerial. The solid hypohalite precipitate forms around the fibers andin the interstices of the fibrous layer. The solid hypohaliteprecipitate is able to form around the fibers of the fibrous layerbecause it is formed in situ on the fibrous material. The hypohaliteprecipitate may be substancially evenly distributed throughout the widthof one or more fibrous layers of substrate material. The hypohaliteprecipitate comprises mixtures and combinations of hypohalite salts.

In one embodiment of the invention, the hypohalite-releasing substrateis a hypochlorite-releasing substrate and the hypohalite precipitate isa hypochlorite precipitate selected from the group consisting of:hypochlorite monohydrate salt, hypochlorite dihydrate salt, hemibasichypochlorite salt, monobasic hypochlorite salt, dibasic hypochloritesalt, anhydrous hypochlorite salt, and mixtures and combinationsthereof.

Cleaning Composition

In one embodiment, the hypohalite-releasing substrate may be impregnatedwith a cleaning composition. If the hypohalite-releasing substrate isimpregnated with a cleaning composition, at least one layer of thesubstrate material may be ‘wet-to-the-touch’ while another layer of thesubstrate may be ‘dry-to-the-touch’. In another embodiment, the entiresubstrate is impregnated with a cleaning composition and the entiresubstrate is ‘dry-to-the-touch’. By ‘dry-to-the-touch’, it is meant thatthe substrate is substantially free of water or other solvents in anamount that would make them feel damp or wet-to-the-touch as compared tothe touch of a wet substrate, for example a wet cleaning wipe. Thecleaning composition may comprise surfactants and additives which arefound in a wide variety of cleaning articles. The cleaning compositionmay be found in the same fibrous layer of the substrate as thehypohalite precipitate or it may be held in a separate layer of thesubstrate material and it may be separated from the hypohaliteprecipitate layer by a moisture impermeable material.

Surfactants

Optionally, surfactants suitable for use in this invention are selectedfrom anionic, non-ionic, amphoteric, zwitterionic surfactants andmixtures thereof. It is especially preferred to use a combination ofanionic and bleach-stable, non-ionic surfactants. The anionic surfactantis selected from bleach-stable surfactants such as alkali metal alkylsulfates, secondary alkane sulfonates (also referred to as paraffinsulfonates), alkyl diphenyl ether disulfonates, fatty acid soaps, andmixtures thereof. Such an anionic surfactant will preferably have alkylgroups averaging about 8 to about 20 carbon atoms. In practice, the useof any other anionic surfactant, this does not degrade chemically whenin contact with a hypohalite bleaching species, is considered suitablefor use in this invention.

An example of a particularly preferred secondary alkane sulfonate isHOSTAPUR SAS, manufactured by Farbwerke Hoechst A.G., Frankfurt, WestGermany. Examples of typical alkali metal salts of alkyl benzenesulfonic acids are those manufactured by Pilot Chemical Company soldunder the trademark CALSOFT. An example of a typical alkali metal alkylsulfate is CONCO SULFATE WR, sold by Continental Chemical Company, whichhas an alkyl group of about 16 carbon atoms. When the electrolyte usedis an alkali metal silicate, it is most preferable to include a solublealkali metal soap of a fatty acid, such as a hexyl to tetradecyl fattyacid soaps. Especially preferred are sodium and potassium soaps oflauric and myristic acid. When used as a component of the inventivecleaning composition, the alkali metal soap of a fatty acid is presentin an amount from above zero to about 10 weight percent of thecomposition.

Examples of preferred bleach-stable, non-ionic surfactants are amineoxides, especially trialkyl amine oxides, as represented in the formulaexpression RR′R″NO, in which R′ and R″ may be alkyls of 1 to 3 carbonatoms and are most preferably methyls, and R is an alkyl of about 10 to20 carbon atoms. When R′ and R″ are both methyl and R is alkyl averagingabout 12 carbon atoms, the structure for dimethyldodecylamine oxide, aparticularly preferred amine oxide, is obtained. Representative examplesof these particular types of bleach-stable, non-ionic surfactantsinclude the dimethyldodecylamine oxides sold under the trademark AMMONYXLO by Stepan Chemical. Yet other preferred amine oxides are those soldunder the trademark BARLOX by Lonza, CONCO XA sold by ContinentalChemical Company, AROMAX sold by Akzo, and SCHERCAMOX, sold by ScherBrothers, Inc. These amine oxides preferably have main alkyl chaingroups averaging about 10 to about 20 carbon atoms. Other types ofsuitable surfactants include amphoteric surfactants such as, forexample, betaines, imidazolines and certain quaternary phosphonium andtertiary sulfonium compounds.

It is suitable to use one or more surfactants in the inventive cleaningsubstrates. The surfactants may be incorporated in the same layer ofsubstrate material as the hypochlorite precipitate or alternativelysurfactants may be included in separate layer or layers of the substratewhere it may be separated from the layer containing the hypochloriteprecipitate. In the inventive composition, total surfactant, whenpresent, is included in an amount ranging from about 0.001 to about 20weight percent of the cleaning composition, preferably in an amountranging from about 0.01 to about 5 weight percent of the composition.For reduced surface residue and to decrease the tendency of thecompositions to contribute to excess foaming, residual filming orstreaking, and particularly for use on glossy or shiny surfaces, totalsurfactant, when present, is included in an amount most preferably fromabout 0.01 to about 1.0 weight percent of the composition.

Optionally, an additional co-surfactant may be added to the disinfectantcomposition of this invention. The bleach stable anionic surfactantsinclude alkali metal alkyl sulfates, alkylarylsulfonates, primary andsecondary alkane sulfonates (also referred to as paraffin sulfonates),alkyl diphenyloxide disulfonates, and mixtures thereof. The anionicsurfactants have alkyl groups preferably averaging about 8 to 20 carbonatoms. The alkyl arylsulfonic acid salts of preference are linearalkylbenzene sulfonates, known as LAS's. Typical LAS's have C 8-16 alkylgroups, non-limiting examples of which include Stepan Company's Biosoftand Pilot Chemical Company's Calsoft. Still further suitable surfactantsare the alkyldiphenylether disulfonates (also called alkyldiphenyloxidedisulfonates), such as, by way of example only, those sold by DowChemical Company under the name “Dowfax,” e.g., Dowfax 3B2. Still otherpotentially suitable anionic surfactants include alkali metal alkylsulfates such as Conco Sulfate WR, sold by Continental Chemical Company,which has an alkyl group of about 16 carbon atoms; and secondary alkanesulfonates such as Hostapur SAS, manufactured by Farbwerke Hoechst AG.

Additives

The disinfectant composition of the present invention may optionally beformulated to include further adjuncts, for example, sequestrants,chelants, hydrotropes, effervescent materials, thickening agents,rheology modifiers, fragrances, coloring agents, pigments (e.g.,ultramarine blue), bleach-stable dyes (e.g., anthraquinone dyes),whiteners, including the optional surfactants, solvents, chelatingagents and builders, which enhance performance, stability or aestheticappeal of the composition. Generally, such adjuncts may be added inrelatively low amounts, e.g., each from about 0.001 to about 5.0 weightpercent of the composition.

Optionally, sequestering agents are suitable for use in the inventive cSequestering agents are selected from the group consisting of metalchelators, metal sequestrants and ion exchange materials known in theart. Preferably, metal chelators and metal sequestrants are selectedfrom the group consisting of the alkali and alkaline earth salts of thephosphates, phosphonates, borates, silicates,polyfunctionally-substituted aromatic chelating agents, ethylenediaminetetra-acetate (EDTA) and ethylenediamine-N,N′-disuccinic acids, ormixtures thereof. Preferred sequestering agents are the silicates andethylenediamine tetra-acetate.

Optionally, polyfunctionally-substituted aromatic chelating agents mayalso be useful in the bleaching compositions herein. See U.S. Pat. No.3,812,044, issued May 21, 1974, to Connor et al. Preferred compounds ofthis type in acid form are dihydroxydisulfobenzenes such as1,2-dihydroxy-3,-5-disulfobenzene. A preferred biodegradable chelatingagent for use herein is ethylene diamine N,N′-disuccinic acid, or alkalimetal, or alkaline earth, ammonium or substituted ammonium salts thereofor mixtures thereof.

The substrate or cleaning composition loaded onto the substrate maycomprise materials that effervesce when combined with water. Thematerials may be within a water-soluble, water-insoluble, orwater-dispersible pouch to slow the effervescent action or to protectthe composition from premature hydration. The materials may comprise apolymeric agent to slow the effervescence. One component of theeffervescent materials may be an acidic material. Suitable for thispurpose are any acids present in dry solid form. Suitable for thispurpose are C2-20 organic mono- and poly-carboxylic acids such as alpha-and beta-hydroxycarboxylic acids; C2-20 organophosphorus acids such asphytic acid; C2-20 organosulfur acids such as toluene sulfonic acid; andperoxides such as hydrogen peroxide or materials that generate hydrogenperoxide in solution. Typical hydroxycarboxylic acids include adipic,glutaric, succinic, tartaric, malic, maleic, lactic, salicylic andcitric acids as well as acid forming lactones such as gluconolactone andgluccrolactone. A suitable acid is citric acid. Also suitable as acidmaterial may be encapsulated acids. Typical encapsulating material mayinclude water-soluble synthetic or natural polymers such aspolyacrylates (e.g. encapsulating polyacrylic acid), cellulosic gums,polyurethane and polyoxyalkylene polymers. By the term “acid” is meantany substance which when dissolved in deionized water at 1%concentration will have a pH of less than 7. These acids may also have apH of less than 6.5 or less than 5. These acids may be at 25° C. insolid form, i.e. having melting points greater than 25° C.Concentrations of the acid should range from about 0.5 to about 80%, orfrom about 10 to about 65%, or from about 20 to about 45% by weight ofthe total composition.

Another component of the effervescent materials may be an alkalinematerial. The alkaline material may a substance that can generate a gassuch as carbon dioxide, nitrogen or oxygen, i.e. effervesce, whencontacted with water and the acidic material. Suitable alkalinematerials are anhydrous salts of carbonates and bicarbonates, alkalineperoxides (e.g. sodium perborate and sodium percarbonate) and azides(e.g. sodium azide). An example of the alkaline material is sodium orpotassium bicarbonate. Amounts of the alkaline material may range fromabout 1 to about 80%, or from about 5 to about 49%, or from about 15 toabout 40%, or from about 25 to about 35% by weight of the totalcomposition.

When the cleaning composition or substrate comprises effervescentmaterials, then the composition may comprise no more than 5%, or no morethan 3.5%, or no more than 1% water by weight of the total composition.Water of hydration is not considered to be water for purposes of thiscalculation. However, water of hydration may be preferred or eliminated.The combined amount of acidic and alkaline materials may be greater than1.5%, or from about 40 to about 95%, or from about 60 to about 80% byweight of the total composition.

The optional hydrotropes are preferably selected from short chainalkylarylsulfonates, salts of benzoic acid, benzoic acid derivatives(such as chlorobenzoic acid), and mixtures thereof. As used herein, arylincludes, without limitation, at least benzene, naphthalene, xylene,cumene and similar aromatic nuclei. These aryl groups can be substitutedwith one or more substituents known to those skilled in the art, e.g.,halo (chloro, bromo, iodo, fluoro), nitro, or C 1-4 alkyl or alkoxy.Most preferred is sodium xylene sulfonate (such as Stepanate SXS,available from Stepan Company).

By way of example, a fragrance such as a fragrance commerciallyavailable from International Flavors and Fragrance, Inc., may beincluded in the inventive composition in an amount from about 0.01 toabout 0.5 weight percent of the composition. Dyes and pigments may beincluded in small amounts in the composition of the present invention.Examples of widely used, suitable pigments include ultramarine blue(UMB) and copper phthalocyanines

Solvents may also be added to the inventive compositions to enhancecleaning and/or disinfectant efficacy of the compositions. The solventsmaybe held separately from the hypohalite precipitate layer of thesubstrate. Alternatively, low levels of solvents, less than 20%, lessthan 10% or less than 5%, maybe held in the substrate in the same layersas the hypohalite precipitate. For example, certain less water solubleor dispersible organic solvents, some of which are advantageously stablein the presence of hypochlorite bleach, may be included. Thesebleach-stable solvents include those commonly used as constituents ofproprietary fragrance blends, such as terpenes and essential oils, andtheir respective derivatives.

The terpene derivatives suitable for the present invention includeterpene hydrocarbons with a functional group. Effective terpenes with afunctional group include, but are not limited to, alcohols, ethers,esters, aldehydes and ketones. Representative examples of each of theabove-mentioned terpenes with a functional group include, but are notlimited to, the following: (1) terpene alcohols, including, for example,verbenol, transpinocarveol, cis-2-pinanol, nopol, iso-borneol, carbeol,piperitol, thymol, alpha-terpineol, terpinen-4-ol, menthol, 1,8-terpin,dihydroterpineol, nerol, geraniol, linalool, citronellol,hydroxycitronellol, 3,7-dimethyl octanol, dihydromyrcenol,beta-terpineol, tetrahydro-alloocimenol and perillalcohol; (2) terpeneethers and esters, including, for example, 1,8-cineole, 1,4-cineole,iso-bomyl methylether, rose pyran, alpha-terpinyl methyl ether,menthofuran, trans-anethole, methyl chavicol, allocimene diepoxide,limonene mono-epoxide, iso-bornyl acetate, nopyl acetate, alpha-terpinylacetate, linalyl acetate, geranyl acetate, citronellyl acetate,dihydro-terpinyl acetate and nerol acetate; and (3) terpene aldehydesand ketones, including, for example, myrtenal, campholenic aldehyde,perillaldehyde, citronellal, citral, hydroxy citronellal, camphor,verbenone, carvenone, dihydrocarvone, carvone, piperitone, menthone,geranyl acetone, pseudo-ionone, alpha-ionone, beta-ionone,iso-pseudo-methyl ionone, normal-pseudo-methyl ionone, iso-methyl iononeand normal-methyl ionone. Terpene hydrocarbons with functional groupswhich appear suitable for use in the present invention are discussed insubstantially greater detail by Simonsen and Ross, The Terpenes, VolumesI-V, Cambridge University Press, 2nd Ed., 1947, which is incorporatedherein in entirety by this reference. See also, commonly assigned U.S.Pat. No. 5,279,758, issued to Choy on Jan. 18, 1994, which isincorporated herein in entirety by this reference.

Cleaning Head

The present invention is directed to a method for forming a solidhypohalite precipitate, preferably a hypochlorite precipitate, on afibrous substrate and composition formed thereof. In one embodiment ofthe invention, the fibrous substrate with a solid hypochloriteprecipitate may be a cleaning head for various household cleaning tools.Such household cleaning tools include but are not limited to, toiletbowl cleaning heads, bath and shower cleaning heads, mop heads,dishwashing tool heads, and the like. In one aspect of the cleaning headembodiment of the invention, it is desirable to have at least onehi-loft layer of the cleaning head. The hi-loft layer of the cleaninghead may be desirable because it will help provide quick release of thesoild hypochlorite material when it is exposed to a fluid. For example,in a cleaning head used for cleaning a toilet bowl, the hi-loft layermay allow the substrate to quickly and effectively release theyhypochlorite precipitate when wetted to efficiently clean and disinfectthe toilet bowl.

The quick release of hypochlorite is essential for some applicationssuch as toilet bowl cleaning and shower cleaning because the userquickly dips the cleaning head in water and then immediately beginscleaning the desired surface. Therefore for the hypochlorite and/orsurfactants must be able to release quickly from the cleaning head toadequately disinfect the surface being cleaned. The present inventionprovides a few significant advantages over the prior art inaccomplishing quick release because the hypochlorite containingsubstrate may be substantially free of binders, adhesives, glue, latex,tacifiying agents and the like. In addition, the present inventioncomprises solid hypochlorite precipitates, such as hypochloritedihydrate salt, which have quick dissolution rates. In addition, unliketraditional solid hypochlorite substrates where the solid particles areattached to the surface the solid hypochlorite precipitate may be evenlydistributed throughout a layer of substrate material or throughout theentire substrate which contributes to a more even release rate ofhypochlorite. In the case of surfactants, quick but sustained release isdesirable so that there is sufficient foam for the consumer to lastthroughout the entire cleaning surface. It is also desirable to havesustained release of the hypohalite component because it will allow thesubstrate to disinfect the entire surface that the user desires toclean.

In another embodiment of the invention, the cleaning head may have morethan one layer of fibrous materials. In the case of a cleaning head fora household cleaning tool it may be desirable to have a scrubby layer asthe top fibrous layer of the cleaning head. The scrubby layer maycomprise an abrasive material comprising: abrasive particulates,abrasive fibers, bristles, foam, and any other abrasive materials knowin the art. The abrasive material may be formed as a separate layer ofthe cleaning head or may be formed on the surface of another layer ofthe cleaning head.

The cleaning head may have other layers of fibrous materials includingbut not limited to an absorbent layer, a fluid impervious layer and atool attachment layer. The absorbent layer may include any suitablefibrous absorbent material. A fluid impervious layer may be located inbetween various layers of the cleaning head to prevent the solidhypochlorite precipitate from being exposed to another layer of fibrousmaterial containing a fluid or containing an active that is reactivewith the solid hypochlorite precipitate. In one embodiment, the fluidimpervious layer is adjacent to the tool attachment layer to prevent thetool attachment layer from becoming saturated with fluid which couldweaken its attachment strength to the rest of the tool assembly. Theattachment layer could be a velco, adhesive, hook and loop, button,mating snap, and any other suitable attachment means. The tool assemblymay be a simple handle, an elongated handle or pole or aninterchangeable cleaning head fitment which may be attached to a widevariety of different mops, brushes, vacuums, brooms, and other suitablehousehold cleaning tools.

Suitable non-limiting examples of household cleaning tools may be foundin the following references. One example of a suitable cleaning head isdescribed in published Application 2005/0217698, which was filed Apr. 1,2004, entitled “Ergonomic Cleaning Pad”, and which is herebyincorporated by reference. In another embodiment of the invention, thecleaning implement comprises the tool assembly disclosed in U.S. Pat.No. 7,065,825, entitled “Cleaning Tool with Gripping Assembly for aDisposable Scrubbing Head”, filed Jun. 23, 2003, which is herebyincorporated by reference. In another embodiment of the invention, thecleaning implement comprises the tool assembly disclosed in U.S. Pat.No. 6,953,299, entitled “Cleaning Implement with Inter-changeable ToolHeads”, filed Jan. 27, 2004, which is hereby incorporated by reference.In another embodiment of the invention, the cleaning implement comprisesthe tool assembly disclosed in U.S. Pat. No. 7,065,838, entitled“Locking Segmented Cleaning Implement Handle”, filed May 19, 2004,hereby incorporated by reference.

In another embodiment of the invention, the cleaning implement comprisesan elongated shaft having a handle portion on one end thereof. The toolassembly may further include a gripping mechanism that is mounted to theshaft to engage the removable cleaning substrate. Examples of suitablecleaning implements are found in US2003/0070246 to Cavalheiro; U.S. Pat.No. 4,455,705 to Graham; U.S. Pat. No. 5,003,659 to Paepke; U.S. Pat.No. 6,485,212 to Bomgaars et al.; U.S. Pat. No. 6,290,781 to Brouillet,Jr.; U.S. Pat. No. 5,862,565 to Lundstedt; U.S. Pat. No. 5,419,015 toGarcia; U.S. Pat. No. 5,140,717 to Castagliola; U.S. Pat. No. 6,611,986to Seals; US2002/0007527 to Hart; and U.S. Pat. No. 6,094,771 to Egolfet al. The cleaning implement may have a hook, hole, magnetic means,canister or other means to allow the cleaning implement to beconveniently stored when not in use.

Housing Systems and Packaging Materials

Suitable packaging materials may be provided by a variety of sources,and include all suitable materials that are moisture impermeable andpreferably heat resistant. It is preferred that the housing or packagingmaterials be hypohalite stable, in that they undergo no significantdegradation. That is, the packaging materials undergo no significantchemical or physical change in structure, properties or form, owing tocontact with the hypohalite compositions employed in the presentinvention. Suitable packaging materials include those materials commonto the art.

Housing systems include both individually packaged disinfectant wipesand bulk packaged one or more disinfectant wipes or other suitabledisinfecting articles. The housing system preferably comprises asealable container, which is substantially impervious to both liquid andgas. The term “container”, refers to, but is not limited to, packetscontaining one or more individual disinfectant wipes and bulkdispensers, such as canisters, tubs and jars, which dispense onedisinfectant wipe at a time, and further feature suitable means toreseal the bulk dispenser between uses to preserve the integrity of thedisinfecting articles. One example is a cylindrical canister dispenserthat hosts a roll of individual wipes, separated by perforations topermit the tearing off of individual wipes for use. Such dispenser isconveniently gripped by the user and held in position while the userremoves a wipe. Preferred are dispensers featuring a resealabledispensing cap and orifice (See, e.g., Chong, U.S. Pat. No. 6,554,156,of common assignment and incorporated herein by reference thereto) thatdispenses individual wipes from a roll and retains the next wipe in aready-to-dispense position, yet allows sealing of the dispensing cap toclose the container against the environment when not in use. A furtherexample, within the scope of the present invention, is to packageindividual wipes in a non-linked manner, in a dispenser permitting theirremoval one at a time, as is the case with many wipe/dispensercombinations known in the art.

Without departing from the spirit and scope of this invention, one ofordinary skill can make various changes and modifications to theinvention to adapt it to various usages and conditions. As such, thesechanges and modifications are properly, equitably, and intended to be,within the full range of equivalence of the following claims.

1. A process for making a hypochlorite-releasing substrate comprisingthe steps of: a. providing at least one layer of fibrous materialcomprising synthetic fibers; b. treating the fibrous layer to aneffective amount of an aqueous alkaline earth salt solution, c. treatingthe fibrous layer with an effective amount of a hypochlorite solution,and d. allowing the aqueous alkaline earth salt solution combine withthe hypochlorite solution to form a solid hypochlorite precipitatearound the fibers in the fibrous material and a liquid phase, and e.removing at least 65% of the liquid phase from the substrate.
 2. Theprocess for making a hypochlorite-releasing substrate according to claim1, wherein the alkaline earth salt solution is selected from the groupconsisting of: magnesium chloride, calcium chloride, calcium hydroxide,magnesium hydroxide and any mixtures or combinations thereof.
 3. Theprocess for making a hypochlorite-releasing substrate according to claim1, wherein the hypochlorite solution comprises compounds selected fromthe group consisting of: sodium hypochlorite, potassium hypochlorite,lithium hypochlorite, calcium hypochlorite, magnesium hypochlorite,hypochlorous acid, and any mixtures or combinations thereof.
 4. Theprocess for making a hypochlorite-releasing substrate according to claim1, wherein the fibrous material comprises fibers selected from the groupconsisting of: natural cellulose, regenerated cellulose, polyester,acrylic, nytril, cellulose ester, olefin, vinyl and any combinations ormixtures thereof.
 5. The process for making a hypochlorite-releasingsubstrate according to claim 1, wherein the fibers are selected from thegroup consisting of: polypropylene, polyethylene, polyester and anymixtures or combinations thereof.
 6. The process for making ahypochlorite-releasing substrate according to claim 1, wherein the solidhypochlorite precipitate contains salts selected from the groupconsisting of: hypochlorite monohydrate salt, hypochlorite dihydratesalt, hemibasic hypochlorite salt, monobasic hypochlorite salt, dibasichypochlorite salt, anhydrous hypochlorite salt, and mixtures orcombinations thereof.
 7. The process for making a hypochlorite-releasingsubstrate according to claim 1 wherein the substrate comprises two ormore layers of fibrous materials.
 8. The process for making ahypochlorite-releasing substrate according to claim 1 wherein the solidhypochlorite precipitate forms around the fibers in the fibrousmaterial.
 9. The process for making a hypochlorite-releasing substrateaccording to claim 1 wherein the solid hypochlorite precipitate adheresto the substrate without the aid of binders, adhesives, glues, ortackifying agents.
 10. The process for making a hypochlorite-releasingsubstrate according to claim 9, further comprising a step of addingbleach stable surfactants to at least one fibrous layer.
 11. A processfor making a hypochlorite-releasing substrate comprising the steps of:a. providing a first layer of fibrous material comprising fibersselected from the group consisting of: natural cellulose, regeneratedcellulose, polyester, acrylic, nytril, cellulose ester, olefin, vinyland any combinations or mixtures thereof, b. treating the first fibrouslayer to an effective amount of an aqueous alkaline earth salt solution,c. providing a second layer of fibrous material comprising syntheticfibers; d. treating the second fibrous layer with an effective amount ofa hypochlorite solution, and e. contacting the first layer of fibrousmaterial with the second layer of fibrous material and allowing theaqueous alkaline earth salt solution combine with the hypochloritesolution to form a solid hypochlorite precipitate.
 12. The process formaking a hypochlorite-releasing substrate according to claim 11, whereinthe alkaline earth salt solution is selected from the group consistingof: magnesium chloride, calcium chloride, calcium hydroxide, magnesiumhydroxide and any mixtures or combinations thereof.
 13. The process formaking a hypochlorite-releasing substrate according to claim 11, whereinat least one of the fibrous material layers is selected from the groupconsisting of: spunbond, meltblown, spunbond meltblown spunbond, carded,wetlaid, airlaid, thermalbonded, hydroentangled, through-air bonded,needled, chemical bonded, and combinations thereof.
 14. The process formaking a hypochlorite-releasing substrate according to claim 11, whereinthe fibers from at least one of the fibrous layers are selected from thegroup consisting of: polypropylene, polyethylene, polyester and anymixtures or combinations thereof.
 15. The process for making ahypochlorite-releasing substrate according to claim 11 furthercomprising the step of adding an additive selected from the groupconsisting of: emulsifiers, pH adjusters, silicones, non-ionicsurfactants, cationic surfactants, amphoteric surfactants, zwitterionicsurfactants, anionic surfactants, soil release agents, soil releasepolymers, antistatic agents, fragrances, fragrance extenders,antimicrobial actives, preservatives, dyes, colorants, viscosity controlagents, antifoaming agents, pearlizing agents, opacifying agents,antioxidants, sunscreens, dye transfer inhibitors, dye fixative agents,dispersants, chlorine scavengers, wetting agents, electrolytes, enzymes,brighteners, heavy metal chelating agents, fabric softener actives, soilsuspending agents, soil release agents, and mixtures thereof.
 16. Aprocess for making a hypochlorite-releasing substrate comprising thesteps of: a. providing at least one layer of fibrous material comprisingsynthetic fibers; b. treating the fibrous layer to an effective amountof an aqueous alkaline earth salt solution, c. treating the fibrouslayer with an effective amount of a hypochlorite solution, and d.allowing the aqueous alkaline earth salt solution combine with thehypochlorite solution to form a solid hypochlorite precipitate aroundthe fibers in the fibrous material and a liquid phase, and e. adding atleast one surfactant to the substrate.
 17. The process of making ahypochlorite-releasing substrate according to claim 16, wherein thesubstrate comprises two or more layers of materials.
 18. The process ofmaking a hypochlorite-releasing substrate according to claim 16, whereinthe surfactant is added to the substrate as a liquid solution whichco-precipitates as the hypochlorite precipitate forms on the substrate.19. The process of making a hypochlorite-releasing substrate accordingto claim 17, wherein the hypochlorite precipitate resides in a fibrouslayer and the surfactant resides in a separate layer of the substrate.20. The process of making a hypochlorite-releasing substrate accordingto claim 16, wherein the surfactant is selected from the groupconsisting of: secondary alkyl sulfates, amine oxides, causticneutralized fatty acids, and any combinations thereof.